Season Three

After the discovery that Rebecca is not a Walker, Sarah and Kevin start looking for Ryan Lafferty (Luke Grimes), who they believe to be their actual half-brother. Although Nora is against this at first, she later changes her mind. She goes to meet Ryan and invites him to stay with her so he can get to know the family. However, it is made apparent later in the season that Ryan may have had ulterior motives for agreeing with Nora's request. Ryan also causes problems between Justin and Rebecca after developing feelings for the latter.

Nora also decides to start a non-profit center for families of those with illnesses and becomes attracted to her architect, Roger.

Meanwhile, Rebecca and Justin struggle to begin a romantic relationship, as they adjust from thinking they were family and as they try to keep the feud between their families from affecting them. Justin finally decides his path in life and applies to medical school. After a brief separation Justin and Rebecca get back together and become engaged at the end of the season.

Kitty and Robert move forward in their decision to adopt a child, while at the same time Robert has secretly decided to run for governor. Kitty writes a tell-all book about her time in politics and working for Robert, and agrees that she can no longer work for him. Robert has a heart attack the day they welcome their new son, Evan, leaving Kitty to take care of them both and causing a rift in their marriage. Kitty becomes close to a single dad she meets in the park.

Kevin accepts a job offer from Robert as lawyer and press secretary after he was not made partner in the prestigious law firm he worked for. As well as trying to handle his new job, Kevin must adjust to married life with new husband Scotty.

Sarah is having trouble finding work as a single mother after leaving Ojai, while her decision to leave the family business has created uneasy feelings within the family, especially with Tommy. Eventually, she decides to risk putting her money into helping 'Greenatopia' a small internet business company which two young, recent college graduates run out of their apartment. She also faces new problems with her daughter, Paige, as she begins to grow up. Sarah eventually goes back to Ojai and must learn to work along side Holly.

After driving Sarah and Saul from Ojai, Tommy decides it's time to get rid of Holly but engages in an illegal transaction to do so. Once he is discovered Tommy runs away to avoid going to prison. After spending time waiting for him to return Julia leaves with Elizabeth to start a new job. The Walkers go to find Tommy in Mexico at the end of the season.

After a fight with Justin, Rebecca flies to New York and meets up with David. After spending some time together David surprises Rebecca at the airport and tells her he has decided to join her on the same flight back to L.A. Holly and David decide to get back together and be a family.

The third season ranked #33 this season, the highest position it has held yet. However, the average number of viewers dropped to around 10.6 million.